The present invention generally relates to the filtration of media or fluids in connection with a fluid preparation, sampling, delivery, and/or testing process. More particularly, the present invention relates to the automated in-line replacement or xe2x80x9cchanging outxe2x80x9d of used or spent filters with unused or new filters.
Filter elements of varying types are utilized to filter media or fluids flowing through a fluid line or circuit which forms a part of a fluid handling system. The fluid system may serve any number of processes involving one or more preparation, sampling and analytical tasks. A few examples include high-through put liquid sample assaying, high-pressure liquid chromatography, and dissolution testing. Filter elements are often installed xe2x80x9cin-linexe2x80x9d with such systems, and for this purpose can be housed within some type of filter unit equipped with fittings adapted for coupling and decoupling with the circuit in which fluid is moving. As with most engineered devices, it is well-known that filter elements have a limited useful life. That is, after a period of service, filters are subject to degradation, clogging and other conditions which render them no longer useful or at least cause them to impede or restrict the performance of the fluid line in which they are installed. Hence, filters must be replaced periodically, preferably according to a predetermined maintenance schedule. Depending on the process with which fluid conveying and filtering are associated, the down-time and effort required in replacing filters can be a significant criterion. It follows that any means by which the task of replacing filters can be automated, or by which the automation of filter replacement can be improved, is welcomed by the pertinent industries.
One approach to addressing the recognized problems associated with filter replacement is disclosed in U.S. Pat. No. 5,450,982 to Van Den Oever. The embodiments disclosed therein provide an automated filter changing apparatus consisting of a cylindrical filter dispensing device, a cylindrical filter clamping device, a cylindrical filter discharge device, and a means for transporting individual filters to these devices. The devices are arranged in either a linear or rotary arrangement. In the linear arrangement, a motor-powered lead screw and associated slide member are utilized to transport the filters. In the rotary arrangement, a turntable is substituted for the slide member.
According to the above-cited disclosure, a vertical stack of filters is loaded into a hollow cylinder of the filter dispenser, and the lowermost filter drops into an aperture of the transporting means when the transporting means reaches the appropriate position. The transporting means then moves the filter to a position under the clamping device. The clamping device is a pneumatic ram through which a portion of a fluid sampling line runs. The ram bears down onto the filter and establishes a connection between the filter and the fluid sampling line, so that fluid flowing through the sampling line passes through the filter and thereby becomes filtered. The filter is then transported to the discharge device, where the filter is positioned under a hollow cylinder and over a second pneumatic ram. The second pneumatic ram forces the filter upwardly into the hollow cylinder, and the filter is retained there with the aid of a retaining ring.
It is believed that there remains a need for a more practical and effective solution to providing an automated method and apparatus for replacing filters, especially filters of the type which operate in-line with a fluid circuit. There is a particular need for automating the replacement of filters which have inlet and outlet fittings extending outwardly from their housings. Such filters are often supplied in a stacked or columnar form in which each filter in the stack is connected to adjacent filters by mating the fittings of adjacent filters together. The present invention therefore provides a novel automated apparatus for changing or replacing filters, especially in-line filters, as described hereinbelow.
The present invention generally provides a filter changing or replacing system comprising a filter dispensing assembly and/or a filter clamping assembly. Each device includes novel attributes which permit the successful implementation of a controlled, automated filter changing process.
The filter dispensing device can be rotated, such as through the use of a motor and associated shaft. The filter dispensing device is adapted to receive filter storage units such as one or more magazines in which a plurality of filters are initially stored as a connected stack. The filter dispensing device includes a filter separating device having a stationary portion. The filter separating device operates to separate one or more stacks of filters into discrete filter units, such that individual filters are sequentially transported from the filter dispensing device, and preferably to a lateral guide track at which filter positioning devices are provided.
The filter clamping assembly is adapted to operate in combination with the filter dispensing device and to receive one or more individual filter units dispensed therefrom, and provides one or more coupling sites which can fluidly communicate with one or more fluid lines. The filter clamping assembly is powered and actuated by means such as a motor and associate lead screw. Alternating or cyclical movement of the filter clamping device decouples used filters from fittings associated with the fluid lines, and couples unused filters to those fittings.
Preferably, a filter position sensing device is provided at the clamping assembly, such as by mounting the sensing device to the lateral guide track, and a clamping position sensing device is additionally provided to monitor the position of a movable portion of the clamping assembly. In this manner, an electronic control unit can be placed in electrical communication with the position sensors and the motors to monitor and control the respective operations of both the filter dispensing device and the filter clamping device, and also coordinate the operations of those devices.
According to a first embodiment of the present invention, a filter dispensing apparatus comprises a rotary member having a longitudinal axis, and a stationary member. The stationary member includes an annular interior surface disposed in coaxial relation to the rotary member. The stationary member also includes an inlet opening, an outlet opening disposed at an axial distance from the inlet opening, and a channel formed on the interior surface. The channel runs along a generally helical path with respect to the longitudinal axis, and has a varying pitch. The pitch of the channel increases with respect to an axial length of the interior surface. The channel communicates with the inlet opening and the outlet opening.
According to a second embodiment of the present invention, a filter dispensing apparatus comprises a rotatable shaft, a filter handling device secured to the shaft and defining a first filter path, and a filter separation device. The filter separation device has an annular interior surface fixedly disposed in coaxial relation to the shaft. The filter separation device includes an entry location disposed in communication with the first filter path, an exit location disposed at an axial distance from the entry location, and a channel formed on the interior surface and defining a second filter path. The channel runs along a generally helical orientation with respect to the shaft, with a varying pitch of the channel increasing with respect to an axial length of the interior surface. The channel communicates with the entry location and the exit location.
According to a third embodiment of the present invention, a filter clamping assembly comprises an actuator device, a first arm, a second arm, a track, and a filter positioning slide. The first arm includes a first fitting disposed in movable relation to the first arm. The second arm is disposed in movable engagement with the actuator device, and includes a second fitting disposed in movable relation to the second arm. The actuator device is adapted to adjust an axial distance between the first arm and the second arm. The track is interposed between the first fitting and the second fitting, and extends along a track direction. The filter positioning slide is slidable along a slide direction transverse to the track direction.
According to a fourth embodiment of the present invention, a filter clamping assembly comprises an actuator device, a first arm, a second arm, a track, a plurality of first biasing members, and a plurality of second biasing members. The first arm includes a plurality of first fittings, with each first fitting disposed in movable relation to the first arm. The second arm is disposed in movable engagement with the actuator device and includes a plurality of second fittings, with each second fitting disposed in movable relation to the second arm. The actuator device is adapted to adjust an axial distance between the first arm and the second arm. The track is interposed between the first fittings and the second fittings. Each of the first biasing members engages a corresponding one of the first fittings for biasing the movement of that first fitting in relation to the first arm. Each of the second biasing members engages a corresponding one of the second fittings for biasing the movement of that second fitting in relation to the second arm.
According to a fifth embodiment of the present invention, an automated filter changing apparatus comprises a filter separation device and a filter clamping device. The filter separation device includes a rotary portion and a stationary portion disposed in coaxial relation to the rotary portion. The stationary portion includes an annular interior surface, an exit location and a channel formed on the interior surface. The channel runs along a generally helical path with respect to the rotary portion, with a varying pitch of the channel increasing with respect to an axial length of the interior surface. The channel communicates with the exit location. The filter clamping device includes a filter guide portion communicating with the exit location, a first fitting, and a second fitting movable with respect to the first fitting.
According to a sixth embodiment of the present invention, an automated filter changing apparatus comprises a filter dispensing device, an actuator device, a first arm, a second arm, and a track. The first arm includes a first fitting disposed in movable relation to the first arm. The second arm is disposed in movable engagement with the actuator device, and includes a second fitting disposed in movable relation to the second arm. The actuator device is adapted to adjust an axial distance between the first arm and the second arm. The track communicates with the filter dispensing device and is interposed between the first fitting and the second fitting.
According to a seventh embodiment of the present invention, an automated filter changing apparatus comprises a filter dispensing device, a filter positioning track, and a filter coupling device. The filter positioning track communicates with the filter dispensing device and defines a plurality of laterally spaced filter coupling sites. The filter coupling device includes a plurality of first fluid fittings and a plurality of second fluid fittings. Each first fluid fitting is disposed over one of the coupling sites, and each second fluid fitting is disposed under one of the coupling sites.
According to an eighth embodiment of the present invention, an automated filter changing apparatus comprises a filter dispensing device, a filter positioning track, a filter clamping device, a first position sensing device, a second position sensing device, and an electronic control unit communicating with the first and second position sensing devices. The filter positioning track is disposed in operative communication with the filter dispensing device and defines a plurality of laterally spaced filter coupling sites. The filter clamping device includes a movable member and a plurality of generally oppositely oriented first and second fluid fittings. Each first fluid fitting is disposed over one of the coupling sites, and each second fluid fitting is disposed under one of the coupling sites. The first position sensing device is disposed in operative alignment with one of the coupling sites. The second position sensing device is disposed in operative alignment with the movable member of the filter clamping device.
According to a ninth embodiment of the present invention, an apparatus for replacing a filter in a fluid line comprises a rotary filter handling device, a stationary filter handling device, a filter guiding device, and a filter clamping device. The rotary filter handling device defines a generally downward first filter path. The stationary filter handling device defines a generally helical second filter path which communicates with the first filter path. The filter guiding device defines a third filter path. The third filter path communicates with the second filter path and is oriented in a generally transverse relation to the first filter path. The filter clamping device communicates with a fluid line, and is adapted for releasable engagement with a filter disposed in the filter guiding device.
According to a tenth embodiment of the present invention, an apparatus for replacing a filter in a fluid line comprises a filter storage device, a filter clamping device, and means for transposing a plurality of filters from a stacked arrangement in the filter storage device to a sequential, lateral arrangement in the filter clamping device.
According to an eleventh embodiment of the present invention, an apparatus for connecting a plurality of filters to a plurality of corresponding fluid lines comprises a filter storage device, a filter clamping device, filter conveying means, and clamping force distributing means. The filter clamping device includes a plurality of pairs of inlet and outlet fittings, with each pair of inlet and outlet fittings are adapted for communication with a fluid line. The filter clamping device is adapted to impart a total clamping force to a plurality of filters received in the filter clamping device to connect each filter, under influence of a portion of the total clamping force, in fluid communication with a corresponding one of the pairs of inlet and outlet fittings. The filter conveying means conveys the plurality of filters from the filter storage device to the filter clamping device. The clamping force distributing means distributes the total clamping force to the plurality of filters to reduce variations among the portions of the total clamping force imparted to each filter by the filter clamping device.
According to a twelfth embodiment of the present invention, an apparatus for connecting a filter to a fluid line comprises a filter storage device, a filter clamping device, filter conveying means, and filter positioning means, The filter clamping device includes an inlet fitting and an outlet fitting, which are adapted for communication with a fluid line. The filter conveying means conveys a filter having first and second fittings from the filter storage device to the filter clamping device. The filter positioning means aligns the first fitting of the filter with the inlet fitting of the filter clamping device, and the second fitting of the filter with the outlet fitting of the filter clamping device.
It is therefore an object of the present invention to provide an apparatus for dispensing one or more filters to a device which subsequently couples the filter to a fluid line or fluid circuit.
It is another object of the present invention to provide an apparatus for dispensing a plurality of filters initially provided in a stacked form wherein the fittings of each filter in the stack are typically mated to the fittings of adjacently situated filters, such that the filter stack encounters a separating device which separates each filter from the other filters, and with the result that each filter is dispensed individually with respect to the other filters.
It is yet another object of the present invention to provide an automated apparatus for replacing one or more existing filters operating within a fluid line with one or more unused filters by dispensing individual, unused filters to a filter clamping device, decoupling the existing filters from the fluid line, positioning the unused filters at appropriate coupling sites of the fluid line, and coupling the unused filters to the fluid line at the coupling sites.
It is still another object of the present invention to provide a filter changing apparatus which coordinates the operations of a filter dispensing device with a filter clamping device, in part by counting the number of individual filters being loaded into the clamping device and by determining when the clamping device has reached an open state at which used filters can be replaced with new filters.
It is a further object of the present invention to provide a filter clamping apparatus which permits used filters to be decoupled from a fluid line for subsequent replacement with unused filters, wherein the filter clamping apparatus can evenly distribute the clamping force needed for connecting each filter with inlet and outlet fittings of the fluid line corresponding to that filter.
It is an additional object of the present invention to provide a filter changing apparatus which includes a filter positioning device that ensures that filters transported by the filter changing apparatus are brought into proper alignment with a filter clamping device.
Some of the objects of the invention having been stated hereinabove, other objects will become evident as the description proceeds when taken in connection with the accompanying drawings as best described hereinbelow.